Each winter, a flu epidemic sweeps the country. Influenza, commonly called "the flu," is an infection of the respiratory tract caused by the influenza virus. The flu is typically spread when an infected person coughs or sneezes the virus into the air. Compared with most other viral respiratory infections, such as the common cold, influenza often causes a more severe illness.

Typical flu symptoms include fever, dry cough, sore throat, runny or stuffy nose, headache, muscle aches and extreme fatigue. Children may experience gastrointestinal problems like nausea, vomiting and diarrhea but such symptoms are not common in adults. Although the term "stomach flu" is sometimes used to describe gastrointestinal illnesses, this is caused by other organisms and is not related to "true" flu.

People usually develop symptoms 1-4 days after they are infected with the flu virus. Adults are able to spread the virus to others even before getting the symptoms through 5-7 days after symptoms start. Children though may be contagious for a longer period of time.

Most people who get the flu recover completely in 1 to 2 weeks, but some people develop serious and life-threatening medical complications, such as pneumonia. In an average year, influenza is associated with more than 20,000 deaths nationwide and more than 100,000 hospitalizations. Complications related to the flu can occur at any age; however, the elderly and people with chronic health problems are at much higher risk than are younger, healthier people.

By far, the single most important way to reduce your chances of getting the flu is to get vaccinated this fall. The best time to get a flu shot is from October through mid-November. However, shots can be taken at any time during flu season. It takes 1-2 weeks, after receiving the shot, for a person to develop protective antibodies.

The flu vaccine is highly recommended for those at high risk for developing serious complications. These groups include all people aged 65 years or older; all people in nursing homes; children and on long-term aspirin therapy; women who are in the second or third trimester of pregnancy during flu season; people of any age with chronic diseases of the heart, lung or kidneys, diabetes, immuno-suppression or severe forms of anemia. The second major group, who should receive the flu vaccine, are those who are in close contact with anyone in the high-risk groups listed above.

Flu shots must be given every year because, the virus that causes influenza is always slightly changing its identity and there are usually many strains in circulation at one time. Each year a new vaccine is made to help protect people from the strains of influenza virus that are expected to make people sick during the coming flu season. The flu shot that has been produced this flu season contains three influenza virus strains designated A/Panama, A/New Caledonia and B/Yamanashi. It takes about 1 to 2 weeks after vaccination for the antibody against influenza to develop and provide protection. Another reason is that antibody resulting from flu vaccine declines over time and antibody levels from one year can be too low to provide protection for the next year.

When the vaccine viruses and circulating viruses are well matched, the flu vaccine is 70-90 percent effective in preventing influenza among healthy adults. In the elderly and those with certain chronic medical conditions, the vaccine is often less effective in preventing illness. However, the vaccine may not prevent everyone who takes it from getting sick, it does reduce the risk of severe illness, hospitalization and death. That's why it's so important, for anyone who wants to reduce his or her risk of getting severely ill from influenza, to receive the vaccine each year.

Common Misconceptions About The Flu:

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